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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

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48 results for Dirac measure

Unified positive mass theorem and Dirac operator study on weighted manifolds.

problem Establishing a unified positive mass theorem for weighted manifolds and smooth metric measure spaces.
method Analyzing Dirac operators on warped product manifolds and applying results to the positive mass theorem.
result Equivalence of weighted positive mass theorem to usual positive mass theorem.

Smooth bundles with rough data maintain Hodge kernel isomorphism.

problem Maintaining Hodge kernel isomorphism for smooth bundles with non-smooth geometric data.
method Analyzing nilpotent differential operators and Hodge-Dirac-type operators under perturbations of geometric data.
result Kernels of Hodge-Dirac operators remain isomorphic under uniform perturbations of geometric data.

We compute the hybrid limit (in the sense of Boucksom-Jonsson) of the family of Kähler-Einstein volume forms on a degeneration of canonically polarized manifolds. The limit measure is a weighted sum of Dirac masses at divisorial valuations, determined by the natural algebro-geometric limit of the family. We also make s…

2019-11-08abs ↗pdf ↗

We define two categories of Dirac manifolds, i.e. manifolds with complex Dirac structures. The first notion of maps I call \emph{Dirac maps}, and the category of Dirac manifolds is seen to contain the categories of Poisson and complex manifolds as full subcategories. The second notion, \emph{dual-Dirac maps}, defines a…

2007-12-17abs ↗pdf ↗

Introduces weak (p,k)(p,k)-Dirac structures in geometric settings.

problem Defining and analyzing new geometric structures.
method Introducing and studying weak (p,k)(p,k)-Dirac structures in TMΛpTMTM \oplus \Lambda^pT^*M.
result Weak (p,k)(p,k)-Dirac structures contain more information than (p,k)(p,k)-Lagrangian structures.

Introduces compatibility between Dirac structures and Nijenhuis tensors.

problem No specific problem stated; focuses on extending Poisson-Nijenhuis structures.
method Introduces compatibility between Dirac structures and (1,1)-tensor fields.
result Properties of Dirac-Nijenhuis structures studied, including connections and integrations.

Given a Dirac subbundle and an isotropic subbundle of a Courant algebroid, we provide a canonical method to obtain a new Dirac subbundle. When the original Dirac subbundle is involutive (i.e., a Dirac structure) this construction has interesting applications, for instance to Dirac's theory of constraints and to the Mar…

2007-02-01abs ↗pdf ↗

We show that a suitable notion of Dirac-Jacobi structure on a generic line bundle LL, is provided by Dirac structures in the omni-Lie algebroid of LL. Dirac-Jacobi structures on line bundles generalize Wade's E1(M)\mathcal E^1 (M)-Dirac structures and unify generic (i.e.~non-necessarily coorientable) precontact distribu…

2015-02-18abs ↗pdf ↗

We introduce Dirac processes, using Dirac delta functions, for short-rate-type pricing of financial derivatives. Dirac processes add spikes to the existing building blocks of diffusions and jumps. Dirac processes are Generalized Processes, which have not been used directly before because the dollar value of non-Real nu…

2015-04-17abs ↗pdf ↗

A classical theorem of Drinfel'd states that the category of simply connected Poisson Lie groups H is isomorphic to the category of Manin triples (d, g, h), where h is the Lie algebra of H. In this paper, we consider Dirac Lie groups, that is, Lie groups H endowed with a multiplicative Courant algebroid A and a Dirac s…

2011-10-07abs ↗pdf ↗

We considered an extension of the standard functional for the Einstein-Dirac equation where the Dirac operator is replaced by the square of the Dirac operator and a real parameter controlling the length of spinors is introduced. For one distinguished value of the parameter, the resulting Euler-Lagrange equations provid…

2006-03-29abs ↗pdf ↗

Study on symplectic Dirac operators on foliations, estimating eigenvalues.

problem Estimating eigenvalues of transversely symplectic Dirac operators.
method Analysis of transversely symplectic structures and use of Weitzenbock formula.
result Estimation of lower bounds for eigenvalues of transversely symplectic Dirac operators.

Extends a theorem for first-order elliptic operators on manifolds.

problem Proving the relative index theorem for general first-order elliptic operators.
method Using boundary value problems and graphical decomposition of elliptically regular boundary conditions.
result Proves the relative index theorem for general first-order elliptic operators.

The paper introduces discrete Dirac structures for mechanics, simplifying dynamics.

problem Formulating discrete mechanics with constraints.
method Developed (±)(\pm)-discrete Dirac structures and induced Dirac structures.
result Discrete Lagrange--Dirac systems are equivalent to (±)(\pm)-discrete Lagrange--d'Alembert equations.

The paper defines Dirac structures on connection spaces and their properties.

problem Defining Dirac structures on spaces of connections.
method Twisted Dirac structures on spaces of irreducible connections over manifolds, described by the Cartan 3-form.
result Spaces of flat connections are endowed with Dirac structures, and their properties are discussed.

We describe infinitesimally Dirac groupoids via geometric objects that we call Dirac bialgebroids. In the two well-understood special cases of Poisson and presymplectic groupoids, the Dirac bialgebroids are equivalent to the Lie bialgebroids and IM-22-forms, respectively. In the case of multiplicative involutive distr…

2014-03-12abs ↗pdf ↗

New LL_\infty algebra governs deformations of Dirac-Jacobi structures.

problem Deformation theory of Dirac-Jacobi structures.
method Using higher derived brackets and split Courant-Jacobi algebroids, an LL_\infty algebra is associated with each Dirac-Jacobi structure.
result There is a one-to-one correspondence between MC elements of the LL_\infty algebra and small deformations of the Dirac-Jacobi structure.

Local gauge freedom in relativistic quantum mechanics is derived from a measurement principle for space and time. For the Dirac equation, one obtains local U(2,2) gauge transformations acting on the spinor index of the wave functions. This local U(2,2) symmetry allows a unified description of electrodynamics and genera…

1997-03-11abs ↗pdf ↗

We introduce the notions of Chern-Dirac bundles and Chern-Dirac operators on Hermitian manifolds. They are analogues of classical Dirac bundles and Dirac operators, with Levi-Civita connection replaced by Chern connection. We then show that the tensor product of canonical and the anticanonical spinor bundles, called V-…

2017-04-20abs ↗pdf ↗

Study perturbs APS boundary conditions for Lorentzian Dirac operators.

problem Maintaining Fredholmness of Dirac operators under perturbations of APS boundary conditions.
method Develop criteria for perturbing compact pairs of projections to remain Fredholm.
result Criteria for perturbing APS boundary conditions without losing Fredholmness.

This paper develops a weighted L2L^2-method for the (half) Dirac equation. For Dirac bundles over closed Riemann surfaces, we give a sufficient condition for the solvability of the (half) Dirac equation in terms of a curvature integral. Applying this to the Dolbeault-Dirac operator, we establish an automatic transversa…

2014-07-25abs ↗pdf ↗

A Dirac structure is a Lagrangian subbundle of a Courant algebroid, LEL\subset\mathbb{E}, which is involutive with respect to the Courant bracket. In particular, LL inherits the structure of a Lie algebroid. In this paper, we introduce the more general notion of a pseudo-Dirac structure: an arbitrary subbundle, $W\sub…

2014-08-22abs ↗pdf ↗

Extends spectral number variance convergence to random matrix ensembles for twisted Laplacians.

problem Spectral number variance convergence for twisted Laplacians and Dirac operators.
method Extends Rudnick's approach to Gaussian ensembles for twisted Laplacians and Dirac operators.
result Convergence to Gaussian ensembles for twisted Laplacians and Dirac operators.

For any nn-dimensional compact spin Riemannian manifold MM with a given spin structure and a spinor bundle ΣMΣM, and any compact Riemannian manifold NN, we show an εε-regularity theorem for weakly Dirac-harmonic maps . As a consequence, any weakly Dirac-harmonic map is proven to be smooth when n = 2. A weak converg…

2008-10-10abs ↗pdf ↗